If you are a photographer, this shouldn’t be a problem. If, however, you have paintings that you need to photograph, there’s an app for that: Google Photo Scan, available for iPhone/iPad or Android. This app guides you through taking a series of photos of your work, combines them, removes glare (from cover glass or reflections from varnish, etc.), and gives you a nice result. Just be certain your phone/tablet camera has sufficient resolution to meet the above requirement – an iPhone 6 probably will not, but a newer phone or tablet might be fine.